A method to in which one shows affection or hunger by 'eating' another person, animals or various inanimate objects. It's often a compliment....or a very hungry person looking for a quick snack. Probably out of you.

It's often a symbol of friendship or lurve. Unless the person has pointy teeth..then it's quite painful.

People have been known to respond to gnaws with : chew, nibble, counter-gnaw, various yells, and death glares.

It's also a wonderful way to greet a person, as shown below. (screennames have been changed so there :p ) taken from real conversations.